Variseal seal and comparison with O and U rings

Variseal, the word comes from the transliteration of "Variseal", which means composite seal and combined seal, usually refers to spring energy storage seal, and is the abbreviation of spring variseal (spring composite seal).

"Fanseal" itself is a transliteration of "composite seal", so there is no need to add the word "seal" after "Fanseal". If you call it according to the custom, you can add this word. Of course, it is better to directly say "spring energy seal" according to Chinese.

The figure on the right shows the typical structure of Variseal, which is divided into two different parts, the inner and outer parts. The outer seal body is made of special functional plastic, and the inner part is made of stainless steel spring made of special material.

The materials of the seal body and the spring are different due to different working conditions and working media. Generally, the materials of the seal body include: pure tetrafluoroethylene, filled tetrafluoroethylene, ultra-high molecular weight polyethylene, polyimide, polyether ether ketone, etc. The materials of stainless steel springs generally include SUS301, SUS304, SUS316 and SUS718.

The external seal body is in contact with the two surfaces to be sealed and acts as a seal, so it requires low friction coefficient, high strength, wear resistance, working medium resistance, and high temperature or low temperature resistance in the working environment.

The internal stainless steel spring provides pressure for the external seal body, so that the seal lip is always tightly pressed against the sealing contact surface to prevent leakage, especially when the internal pressure is low, zero pressure or even negative pressure, The spring is the only source of sealing pressure. The requirements for the spring are relatively simple: high and low temperature resistance to the environment, corrosion resistance, and relatively constant elastic force. Although these requirements are not many, they are not easy to achieve. The material, process and shape of the spring have high requirements.

Variseal is a sealing form developed in recent years. Like the combined seals such as Gray ring and Step seal, it fully utilizes the superior performance of each component material, so that the overall performance far exceeds any single material seal. Compared with previous seals in various forms, it has both significant advantages and obvious defects.